There is another aspect to this: since 1957 or so a lot of people seem
to have been confused about what a grammar is supposed to do. Is a
grammar supposed to account for native speakers' judgments about
grammaticality (synonomy, ambiguity,...) or account for grammaticality
(synonomy, ambiguity,...)? These are not the same thing!
Judging a sentence to be ambiguous is an ACT. That a sentence is
ambiguous is certainly not.
To take a well-worn example:
Present to a class the sentence "I heard the girl playing my song", and
poll them on amibiguity.
I submit that the majority will judge it to be unambiguous (I have done
this many times). Do you want your grammar to account for this fact? Or
do you want your grammar to account for the fact that the sentence IS
multiply ambiguous (whether or not particular people judge it so)?
Notions such as "performance" and "the ideal speaker-hearer" were
designed to collapse the distinction in an odd sort of way. The real
intent, though, was to get linguists out of the people business. No
actual person is this ideal speaker-hearer, so none should be polled.
And of course no such ideal can be polled about anything either. Exit
polling (from linguistics).
Of course, anyone who continues using expressions like
"judgments/intuitions of the native speaker" is going to continue to
face student unrest (if not mutiny) in Syntax I, because the audience is
going to take such expressions at their face value.

Before we can discuss this, wouldn't we have to be able to
show that OT is other than all-powerful? I mean if it can
capture anything desired constraint, then on the one hand,
there is no point trying to find an inadequacy, and on
the other, that very fact IS the biggest possible inadequacy.
Alexis MR